The use of statin agents in patients with acute coronary syndromes (ACSs) remains an area of intense clinical interest. Statin therapy has an established secondary preventive benefit in patients with coronary artery disease, and its extension to ACS seems logical. A number of observational studies have shown an association between initiation of statin therapy early in ACS and improved clinical outcome. Additionally, 4 randomized controlled trials have examined the use of statin therapy for ACS: the Myocardial Ischemia Reduction with Aggressive Cholesterol Lowering (MIRACL) study, the Pravastatin Turkish Trial, the Fluvastatin on Risk Diminishing After Acute Myocardial Infarction (FLORIDA) study, and the Lipid-Coronary Artery Disease (L-CAD) study. Three of these trials showed a benefit with early initiation of statin therapy, whereas 1 trial demonstrated neither benefit nor harm. All the available trials lacked the power and design to sufficiently evaluate whether early initiation of statin therapy reduces mortality and reinfarction in patients with ACS. Four ongoing trials have been designed and sufficiently powered to determine whether statin therapy reduces the risk of death and reinfarction when initiated early in ACS treatment. A body of evidence suggests that the pleiotropic actions of statin agents might modulate benefit in ACS. This article summarizes the available data and provides a rationale for early initiation of statin therapy for patients with ACS.